Trackball

For the game, seeTrac Ball.

ALogitechtrackball

The original version of theKensingtonExpert Mouse can use a standardAmerican pool ballas a trackball.

Atrackballis apointing deviceconsisting of aballheld by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down ballmousewith an exposed protruding ball.Users roll the ball to position the on-screenpointer,using theirthumb,fingers,or the palm of thehand,while using the fingertips to press the buttons.

With most trackballs, operators have to lift their finger, thumb or hand and reposition in on the ball to continue rolling, whereas a mouse would have to be lifted itself and re-positioned. Some trackballs have notably low friction, as well as being made of a dense material such asphenolic resin,so they can be spun to make them coast. The trackball's buttons may be in similar positions to those of a mouse, or configured to suit the user.

Large trackballs are common onCADworkstations for easy precision.Before the advent of thetouchpad,small trackballs were common onportable computers(such as theBlackBerry Tour) where there may be no desk space on which to run a mouse. Some small "thumballs" are designed to clip onto the side of thekeyboardand have integral buttons with the same function as mouse buttons.

History

The trackball was invented as part of a post-World War II-era radar plotting system namedComprehensive Display System(CDS) byRalph Benjaminwhen working for the BritishRoyal NavyScientific Service.Benjamin's project usedanalog computersto calculate the future position of target aircraft based on several initial input points provided by a user with ajoystick.Benjamin felt that a more elegant input device was needed and invented aball trackersystem called theroller ballfor this purpose in 1946.The device was patented in 1947,but only a prototype using a metal ball rolling on two rubber-coated wheels was ever builtand the device was kept as a military secret.Production versions of the CDS used joysticks.

The CDS system had also been viewed by a number of engineers fromFerranti Canada,who returned to Canada and began development of theRoyal Canadian Navy'sDATARsystem in 1952. Principal designers Tom Cranston, Fred Longstaff andKenyon Taylorchose the trackball as the primary input, using a standardfive-pin bowlingball as the roller. DATAR was similar in concept to Benjamin's display, but used adigital computerto calculate tracks, and sent the resulting data to other ships in a task force usingpulse-code modulationradio signals.

DATAR's trackball used four disks to pick up motion, two each for the X and Y directions. Several additional rollers provided mechanical support. When the ball was rolled, the pickup discs spun and contacts on their outer rim made periodic contact with wires, producing pulses of output with each movement of the ball. By counting the pulses, the physical movement of the ball could be determined.

Since 1966, the American companyOrbit Instrument Corporationproduced a device namedX-Y Ball Tracker,a trackball, which was embedded into radar flight control desks.

A similar trackball device at the GermanBundesanstalt für Flugsicherungwas constructed by a team aroundRainer Mallebreinof TelefunkenKonstanzas part of the development for theTelefunkencomputer infrastructure around the main frameTR 440,process computerTR 86and video terminalSIG 100-86,which began in 1965.This trackball was calledRollkugel(German for "rolling ball" ). Somewhat later, the idea of "reversing" this device led to the introduction of the first computerball mouse(still namedRollkugel,modelRKS 100-86), which was offered as an alternative input device to light pens and trackballs for Telefunken's computer systems since 1968.

In later trackball models the electrical contacts were replaced by anoptical chopperwheel, which had small slots cut into it in rather than electrical contacts. With an LED for illumination from one side and an optical sensor on the other, rotation of the wheel periodically blocks and unblocks the light, so the sensor produces electrical pulses to indicate that rotation is occurring.

Mice used the same basic system for determining motion, but had the problem that the ball was in contact with the desk ormousepad.In order to provide smooth motion the balls were often covered with an anti-slip surface treatment, which was, by design, sticky. Rolling the mouse tended to pick up any dirt and drag it into the system where it would clog the chopper wheels, demanding cleanup. In contrast the trackball is in contact only with the user's hand, which tends to be cleaner. In the late 1990s both mice and trackballs began using direct optical tracking which follows dots on the ball, avoiding the need for anti-slip surface treatment.

As with modern mice, most trackballs now have an auxiliary device primarily intended for scrolling. Some have ascroll wheellike most mice, but the most common type is a “scroll ring” which is spun around the ball. Kensington's SlimBlade Trackball similarly tracks the ball itself in three dimensions for scrolling.

As of 1989and into the 2020s, two major companies developed and produce consumer trackballs,LogitechandKensington,although Logitech has narrowed its product line to two models. Other smaller companies occasionally offer a trackball in their product line.Microsoftproduced popular models including The Microsoft Trackball Explorer, but has since discontinued all of its products.

In September 2017 Logitech announced release of MX-Ergo Mouse,which was released after 6 years of its last trackball mouse.

Special applications

See also:List of trackball arcade games

LogitechCordless TrackMan Wheel

AnApple Pippingamepadwith a trackball

Large trackballs are sometimes seen on computerized special-purpose workstations, such as the radar consoles in anair-traffic controlroom orsonarequipment on a ship or submarine. Modern installations of such equipment may use mice instead, since most people now already know how to use one. However, military mobile anti-aircraft radars, commercial airliners (such asAirbus A380andAirbus A350) and submarine sonars tend to continue using trackballs, since they can be made more durable and more fit for fast emergency use. Large and well made ones allow easier high precision work, for which reason they may still be used in these applications (where they are often called "tracker balls" ) and incomputer-aided design.

Trackballs have appeared invideo games,particularly earlyarcade games(see aList of trackball arcade games). In March 1978,SegareleasedWorld Cup,anassociation football gamewith trackball controls.In October 1978, Atari releasedAtari Football,which popularized the use of a trackball, with the game's developers mentioning it was inspired by an earlier Japanese association football game.Other notable trackball games include Atari'sCentipedeandMissile Command– Atari trademarked it "TRAK-BALL".

Consoletrackballs, now fairly rare, were common in the early 1980s: theAtari 2600and5200consoles, as well as the competingColecoVisionconsole, though using ajoystickas their standard controller, each had one as an optionalperipheral.TheApple Pippin,a console introduced in 1996, had a trackball built into itsgamepadas standard.Trackballs were occasionally used in e-sports prior to the mainstreaming ofoptical micein the early 2000s because they were more reliable than ball mice, but now they are extremely rare because optical mice offer superior speed and precision.Trackballs remain in use in pub golf machines (such asGolden Tee) to simulate swinging the club.

Trackballs have also been regarded as excellent complements to analogjoysticks,as pioneered by the Assassin 3D, a trackball released in 1996 with joystick pass-through capability.Later in 1996,Mad Catzreleased thePanther XL,which was based on the Assassin 3D. This combination provides for two-hand aiming and a high accuracy and consistency replacement for the traditional mouse and keyboard combo generally used onfirst-person shootergames. Many such games natively support joysticks and analog player movement, like Valve'sHalf-Lifeand id Software'sQuakeseries.As of 2020,one professionaleSportplayer was known for using a trackball.

Trackballs are provided as the pointing device in somepublic internet access terminals.Unlike a mouse, a trackball can easily be built into a console, and cannot be ripped away or easily vandalized. Two examples are the Internet browsing consoles provided in some UKMcDonald'soutlets, and theBTBroadband Internet publicphone boxes.This simplicity and ruggedness also makes them ideal for use in industrial computers.

Because trackballs for personal computers are stationary, they may require less space for operation than amouse,simplifying use in confined or cluttered areas such as a small desk or arack-mountedterminal. They are generally preferred in laboratory setting for the same reason.

Trackballs were often included in laptop computers, but since the late 1990s these have been replaced bytouchpadsandpointing sticks.Trackballs are still used as separate input devices with standard desktop computers, but this application is also moving to touchpads due to the prevalence ofmulti touchgesture control in new desktop operating systems.

Ergonomics

LogitechTrackMan Marble Wheel

People with a mobility impairment use trackballs as anassistive technologyinput device. Access to an alternative pointing device has become even more important for them with the dominance of graphically-oriented operating systems. There are many alternative systems to be considered. The control surface of a trackball is easier to manipulate and the buttons can be activated without affecting the pointer position.

Trackball users also often state that they are not limited to using the device on a flat desk surface. Trackballs can be used whilst browsing a laptop in bed, or wirelessly from an armchair to a PC playing a movie. They are also useful for computing on boats or other unstable platforms where a rolling deck could produce undesirable input.

Trackballs are generally either thumb-operated, with a ball about an inch in diameter or smaller moved by one digit (almost always the thumb) and the buttons clicked by others, or finger-operated, with a ball over two inches in diameter operated by the middle fingers and the buttons by the thumb and little finger. Users favor one format or another for reasons of comfort, mobility, precision, or because it reduces strain on one part of the hand/wrist. Most, but not all,finger-operated designs are symmetrical in design, making themusable by both hands,while thumb-operated designs are by their nature asymmetric or “handed,” allowing the smallest examples to be held in the air. Thumb-operated trackballs are not generally available in left-handed configurations, due to small demand.

Some computer users prefer a trackball over the more common mouse for ergonomic reasons. There seems to be no conclusive evidence from studiesperformed to determine which type of pointing device works best for most applications. Application users are encouraged to test different devices, and to maintain proper posture and scheduled breaks for comfort. Some disabled users find trackballs easier since they only have to move their thumb relative to their hand, instead of moving the whole hand, while others incur unacceptable fatigue of the thumb. Elderly people sometimes have difficulty holding a mouse still whiledouble-clicking;the trackball allows them to let go of the ball while using the button.

At times when a user is browsing menus or websites rather than typing, it is also possible to hold a trackball in the right hand like a television remote control, operating the ball with the right thumb and pressing the buttons with the left thumb, thus giving the fingers a rest.

Mobile devices

Nexus Onewith a trackball

Some mobile devices have trackballs, including those in theBlackBerryrange, theT-Mobile Sidekick 3,and many earlyHTCsmartphones.These miniature trackballs are made to fit within the thickness of a mobile device, and are controlled by the tip of a finger or thumb. These have mostly been replaced on smartphones by touch screens, although on the BlackBerry range they were replaced by an "optical trackball" or "optical trackpad"before later being replaced with touch screens.

On mice

In lieu of ascroll wheel,some mice include a tiny trackball sometimes called ascroll ball.A popular example is Apple'sMighty Mouse.Mice with a larger trackball on a side may be designed to stay stationary, using the trackball to move the mouse cursor instead of moving the mouse.

See also

• Touchpad
• Pointing stick
• Mechanical mouse